Six months ago and 3,000 miles later after having a throttle body coolant hose replaced by a Jaguar dealer I was greeted by a low coolant message the other day. Sure enough after checking with the motor running, the coolant level was below the low indicator in the expansion tank. After the system had cooled, the level had fallen several more inches leaving the tank about half full.

I dropped the underbody diffuser and found the pads wet/damp (not drenched) with coolant and a substantial amount of dried coolant all over the transmission housing. I did find a small bit of wet coolant on a line as well and the familiar sweet smell of burning coolant. Otherwise I could see nothing else. Please note the previous leak was discovered the same way so I can't say for certain whether it was the same dried coolant from 6 months ago or whether it was additional.

I disassembled the top of the super charger and throttle body and found a very small amount of wet coolant pooled inside of a hole on the left side of the super charger. There was also dried coolant in on the right side where the Jag dealer replaced the hoses and some other hoses that felt "oily damp" like old coolant. Again, not certain if this is how it was after the dealership performed the repairs.

I washed everything clean on top to get rid of the residue, grease, dirt and dried coolant and left it to dry before reassembly and running the motor again.

Everything looks fine and I can't find any leaks.

Since the repair last July the car has spent most of the time in storage and I have not paid much attention to things like dirt in the engine compartment or coolant levels.

Two other times the dealer performed coolant service over the past two years, one time for a coolant flush that soon after prompted a low coolant level warning solved by topping off the expansion tank with about a gallon of coolant and last January the expansion tank replacement left me with the same low coolant requiring another top off. This leaves me to wonder if perhaps yet again another case of the dealer not using enough coolant when they replaced the hoses and the residue I am seeing is from when they spilled fluid replacing the hoses.

Is it possible for spilled coolant to last 6 months/3000 miles and not completely dry? Does any of this may sense?

 

I have to say it seems unlikely the stuff will hang around for 6 months. The water element will quickly evaporate, and ethylene glycol, the anti-freeze component, breaks down in air in about 10 days.

 

Topping off with a gallon! That's a helluva lot!

It does seem that the dealer is doing a poor job and not filling/bleeding the air out properly.

I am not familiar with the 4.2l engine but suspect that this engine requires more attention to bleeding the air out after refilling than the non supercharged versions.

Silly question but are you aware of the level indicator in the tank?

Do not use dealers unless you have to, use a local indy.

 

Thanks for the replies. I too would have guessed the fluid would not remain for so long, but I had to ask since I cannot find a leak anywhere and my previous experiences with inadequate fluid top off. I'm tempted to button everything back up, top off the tank and drive it until and if the level drops unless someone has any idea of some place else to look for a leak.

One other note and not certain if it is of any value, but I attempted to pressurize the system with a hand pump and was unable to get it to hold any pressure as I pumped.

 

I'd say you still have a leak, or there is a lot of air in the system somewhere. When you bleed the system you have to bleed the intercoolers as well. It should hold pressure.

Stu

 

I thought the intercoolers and engine cooling are on different systems. My S/C still has green coolant, the other system has orange.

 

Here's a pic of the wet coolant I was talking about on the LH side of the super charger. It is down in those two holes. None of the hoses are wet and most of them are at the rear of the motor around the throttle body and away from this area so can't figure where it came from.

 

hay guys i am losing coolant in my jag s type 2.7d it smells in my cabin , the windows get all foogy when i turn on the a/c and today its very cold and i cant turn the heating on it only blows cold air what do you think ? that the heating core problem or evaporator core problem????

 

My n/a xk8 has two heater hoses under the intake manifold, and I have read that the s/c versions are worse on those hoses (still the same place) and they have had to have the whole thing pulled to replace them. If you look around on the xk8-xkr subforum, you'll see lots of threads...oh, and lots of pics in the s-type forum too, the R's over there are well documented with the heater hose leak under the s/c

 

Thank you for the info. I searched and found a lot of useful info in the STR forums. The EVIL hose referred to frequently is the hose the dealer supposedly replaced 6 months/3000 miles ago so could it be that again? I stopped by the dealer and they think there is a chance what I am seeing is 6 month old fluid and that perhaps it took awhile for the air to work its way out.

I put everything back together topped off the coolant with 2 litres of fluid. When I have time, I'll drive the car and monitor fluid level.

Unless someone else has some other theories.

 

Old antifreeze will leave a film for quite some time, so I do believe its possible that is what you are seeing. If there is any leak as severe as the low fluid and fluid trail suggests, you will certainly find more once its topped off. Just keep checking and hope for the best

RyeJag

 

Only way to be sure is clean out your puddles really well...blow some brake cleaner in there, and wait and see. It may have pooled so much, that when the water from the coolant evaporated, the glycerin (as ryejag mentioned above) only remained. Theoretically, only being six months and cool temperatures, that could be possible.

 

So after topping off and driving a few hundred miles, the coolant level has dropped an inch.

I spoke with the Jag dealer who performed the coolant repairs last July and they are out of ideas as well since there is nothing left to leak.

Any other ideas?

 

Has the dealer pressure tested the cooling system? there could be leaks from other hoses, the radiator, the supercharger, or much less likely an internal engine leak ( head gasket). I would continue to watch and fill the tank. I suspect you will find it eventually. It could be simply pooly bleed from excess air and that may work its self out over time.

You may also want to clean and or change the reservoir tank cap. It also could be a source of fluid loss.

When the oil is changed next, it can be checked for potential engine coolant loss as well. The coolant will collect at the bottom of the oil pan.

good luck

RyeJag

 

Yes, it will not hold pressure as mentioned earlier. Oil was changed and no notice of coolant mixed in. Expansion tank and cap are new as of about a year ago. No sign of fluid anywhere at the front of the car.

As mentioned before, there was plenty of coolant residue all over the throttle body area and hoses as well as the transmission housing and underbody diffuser so I cleaned everything thoroughly and it has all remained clean and dry.

I find it odd it took about 3,000 miles for the air to work its way out, if that is the case. I guess only time and mileage will tell.

 

After a few hundred more miles and 2 inches lower on the coolant plus a strong increase in the smell of burnt coolant, I decided took poke around in complete darkness at night with a flashlight. Sadly I finally confirmed there is a leak.

Top of the super charger, throttle body, hoses, etc are still perfectly clean and dry but a very obvious and very large pool of coolant is sitting directly below the throttle body.

The plan now is to take it back to the dealer. This will be the third time it goes back to them for service in this area, certainly hope this is something related to their previous repairs and don't have to come out of pocket again.

 

I had a coolant leak that was solved by replacing the thermostat housing. It's made of plastic and will fail with time. Mine started with a pin sized leak that eventually grew to the size of a small gash along the seam of the housing. A Relatively inexpensive repair.

 

Matt, that's a miracle.
The S/C gets its juices from the bottom radiator hose.
I can only guess you undid the big hex bleed nut and it was still full of the old coolant.

 

I probably did...I need to learn that new system soon.

 

I finally gave up trying to find the leak and took it to a different Jaguar dealer. The original leak repair @ $600 which did not fix the leak involved the following 2 throttle body hoses, according to the work order AJ811758 & AJ89746. The new Jaguar dealer service facility says 3 more throttle body hoses need to be replaced C2C28144 & qty 2 of C2C1984 @ an additional $600.

I didn't think there were that many throttle body coolant hoses, if someone has a parts diagram, that would be really helpful so I can see for myself.

I also think it quite a coincidence this occurred after the dealer replaced the throttle body.